Kenkichi Oki, Headed Global Ad Agency

TOKYO — Kenkichi Oki, 72, president of a worldwide advertising agency and a U.S. government witness in the postwar treason trial of ``Tokyo Rose,`` has died of liver failure in a Tokyo hospital.

Mr. Oki, who was born in Sacramento, Calif. and founded Standard Advertising Inc. in 1958 with headquarters in Tokyo, died April 20. The company has branches in Los Angeles and throughout Asia.

Mr. Oki graduated from New York University and went to Japan in 1939 on what he testified was family business.

A year later, he turned in his American passport and became a Japanese citizen. At the time, he went to work for the international department of NHK, the Japanese broadcasting agency.

At Radio Tokyo in World War II, Mr. Oki was production supervisor for

``Zero Hour,`` a propaganda broadcast to demoralize American soldiers in the Pacific. It featured, among other things, popular American tunes interspersed with commentaries by women trying to sow war-weariness among homesick Americans. The women came to be known collectively as ``Tokyo Rose.`` One of the women was a U.S. citizen, Iva Toguri D`Aquino, and the nickname stuck to her. When she sought after the war to return to the United States, she was prosecuted for treason.

At D`Aquino`s trial in 1949 in San Francisco, Mr. Oki detailed her broadcasting activities and said she had understood the program`s purpose. Despite her assertions that she had acted under duress and was an entertainer rather than a propagandist, she was convicted and sentenced to 10 years in prison and fined $10,000. She was released after 6 1/2 years and was pardoned by President Gerald Ford.